In mines, rock drilling rigs and other mining vehicles are used to perform operations according to work cycles of mining work devices at pre-planned work sites. After the necessary tasks according to the work cycle, such as borehole drilling, have been performed, the mining vehicle is moved to the next work site and a new work cycle is started. In underground mines, in particular, mining vehicles are generally used, in which driving energy for operations according to the work cycles is electricity from an electrical network of the mine. By contrast, transfer drives between work sites are performed by means of driving energy obtained by using a combustion engine, typically a diesel engine, whereby electric cables or the like do not restrict the transfer drives. However, exhaust gases and noise from a combustion engine cause problems in mines. In addition, a combustion engine requires a lot of space on the carriage of the vehicle and necessitates regular maintenance. A combustion engine also has adverse effects on fire safety of the mine, since it has hot surfaces and it is also necessary to store and handle flammable fuel in the vehicle and the mine.
Mining vehicles that are continuously connected to the electrical network of the mine are also used in mines. Mining vehicles that have an electric motor, and typically an electric motor with a constant rotation speed, are used. Power required by the work phase may then be adjusted with hydraulic components, and the electric motor obtains the electric current and load power defined by the energy consumption of the work phase from the electrical network of the mine. Further, the movement of the mining vehicle is then typically bound to the electrical network or at least to a cable connected thereto and coiled in the mining vehicle or at the fixed electrical network.
U.S. Pat. No. 7,053,568, for example, presents a battery-driven mining vehicle. The publication describes, in particular, the use and positioning of a battery and alternating current motors as components of drive transmission.
U.S. Pat. No. 5,293,947 presents a mining vehicle that receives its electric supply from an overhead busbar system. The mining vehicle also has a switch for selecting whether the energy used by the mining vehicle is taken from the electrical network or from an auxiliary energy source, such as a battery or a diesel motor, in the mining vehicle. When energy is taken from an auxiliary energy source, the mining vehicle can be moved short distances without connecting the mining vehicle to the overhead electrical network.
Application WO 2010/061058 discloses a mining vehicle which is connected to an external electrical network at a work site. An energy storage of the vehicle is charged during a work cycle defined by an excavation plan when the vehicle is at the work site. After this work cycle is performed, electricity obtained from the energy storage is used in a transfer drive.